Nurse anesthetists' perceptions and experiences of managing emergence delirium: A qualitative study.

BACKGROUND: This study employs a descriptive phenomenological approach to investigate the challenges anesthesia nurses face in managing emergence delirium (ED), a common and complex postoperative complication in the post-anesthesia care unit. The role of nurses in managing ED is critical, yet research on their understanding and management strategies for ED is lacking. AIM: To investigate anesthetic nurses' cognition and management experiences of ED in hopes of developing a standardized management protocol. METHODS: This study employed a descriptive phenomenological approach from qualitative research methodologies. Purposeful sampling was utilized to select 12 anesthetic nurses from a tertiary hospital in Shanghai as research subjects. Semi-structured interviews were conducted, and the data were organized and analyzed using Colaizzi's seven-step analysis method, from which the final themes were extracted. RESULTS: After analyzing the interview content, four main themes and eight subthemes were distilled: Inefficient cognition hinders the identification of ED (conceptual ambiguity, empirical identification), managing diversity and challenges (patient-centered safe care, low level of medical-nursing collaboration), work responsibilities and pressure coexist (heavy work responsibilities, occupational risks and stress), demand for high-quality management (expecting the construction of predictive assessment tools and prevention strategies, and pursuing standardized management processes to enhance management effectiveness). CONCLUSION: Nursing managers should prioritize the needs and suggestions of nurses in order to enhance their nursing capabilities and provide guidance for standardized management processes.

Metabolomics analysis revealed the neuroprotective role of 2-phosphoglyceric acid in hypoxic-ischemic brain damage through GPX4/ACSL4 axis regulation.

Hypoxic-ischemic brain damage (HIBD) is a cerebral injury resulting from the combination of ischemia and hypoxia in neonatal brain tissue. Presently, there exists no efficacious remedy for HIBD. A mounting body of evidence indicates that dynamic metabolites formed during metabolic procedures assume a vital role in neuronal maturation and recuperation. However, it remains unclear whether any endogenous metabolites are involved in the pathogenesis of HIBD. Here, an untargeted metabolomics analysis was conducted by gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry (GC/LC-MS) in OGD/R (oxygen-glucose deprivation/reoxygenation)-induced HT-22 cells. We observed that ferroptosis signaling plays an essential role in HI-induced neuronal injury. Interestingly, we also found that the differentially expressed metabolite, 2-phosphoglyceric acid, significantly improved the neuronal cell survival of OGD/R HT-22 cells by inhibiting ferroptosis. Moreover, 2-phosphoglyceric acid effectively rescued the cell activity of HT-22 cells treated with the ferroptosis inducer RSL-3. Furthermore, 2-phosphoglyceric acid alleviated cerebral infarction and reduced HIBD-induced neuronal cell loss of the central nervous system in neonatal rats by regulating GPX4 expression. Taken together, we found that 2-phosphoglyceric acid, which was downregulated in HT-22 cells induced by OGD/R, exerted neuronal protective effects on OGD/R-treated HT-22 cells and HIBD-induced neonatal rats by inhibiting hypoxic-ischemic-induced ferroptosis through the regulation of the GPX4/ACSL4 axis.

A new strategy for accelerating recovery of anaerobic granular sludge after low-temperature shock: In situ regulation of quorum sensing microorganisms embedded in polyvinyl alcohol sodium alginate.

Low-temperature could inhibit the performance of anaerobic granular sludge (AnGS). Quorum sensing (QS), as a communication mode between microorganisms, can effectively regulate AnGS. In this study, a kind of embedded particles (PVA/SA@Serratia) based on signal molecule secreting bacteria was prepared by microbial immobilization technology based on polyvinyl alcohol and sodium alginate to accelerate the recovery of AnGS system after low temperature. Low-temperature shock experiment verified the positive effect of PVA/SA@Serratia on restoring the COD removal rate and methanogenesis capacity of AnGS. Further analysis by metagenomics analysis showed that PVA/SA@Serratia stimulated higher QS activity and promoted the secretion of extracellular polymeric substance (EPS) in AnGS. The rapid construction of EPS protective layer effectively accelerated the establishment of a robust microbial community structure. PVA/SA@Serratia also enhanced multiple methanogenic pathways, including direct interspecies electron transfer. In conclusion, this study demonstrated that PVA/SA@Serratia could effectively strengthen AnGS after low-temperature shock.

Anterior Segment Biometry During Accommodation After Posterior Chamber Phakic Implantable Collamer Lens Implantation.

PURPOSE: To evaluate the dynamic changes in anterior segment parameters during accommodation following Implantable Collamer Lens (ICL) implantation with swept-source optical coherence tomography (SS-OCT). METHODS: Under the accommodation of 0.00 diopters (D), 3.00 D, and maximum amplitude, SS-OCT was used to examine the anterior segment parameters, including ICL vault, ICL depth (the distance between the corneal endothelium and the posterior surface of ICL), crystalline lens thickness, anterior chamber depth, and various parameters of the anterior chamber angle, comprising angle opening distance, angle recess area, trabecular iris space area, and trabecular iris angle. RESULTS: During accommodation, the ICL vault showed a significant decrease from baseline (536 ± 278 µm) to 3.00 D (522 ± 281 µm), followed by an increase from 3.00 D to maximum amplitude (548 ± 306 µm) (analysis of variance [ANOVA], P < .001). Four eyes (2.61%) exhibited a decrease in ICL vault to less than 100 µm (47 ± 32 µm) at maximum accommodation. The ICL depth decreased significantly as accommodation increased (ANOVA, P < .001). Crystalline lens thickness increased, whereas anterior chamber depth decreased during accommodation (ANOVA, P < .001). The anterior chamber angle widened during 3.00 D of accommodation but narrowed at maximum accommodation, leading to significant changes in the angle opening distance, angle recess area, trabecular iris space area, and trabecular iris angle during accommodation (ANOVA, P < .001 for all). CONCLUSIONS: The anterior segment, including ICL vault and anterior chamber angle, undergo significant dynamic changes during accommodation. These accommodative changes may require careful monitoring for the surgery design of ICL implantation. [J Refract Surg. 2024;40(3):e164-e172.].

Assessment of the association between D-dimer levels and clinicopathological characteristics of pancreatic cancer and its role in prognosis: A systematic review and meta-analysis.

According to previous studies, D-dimer levels are associated with the prognosis of patients with pancreatic cancer (PC). However, the results of current studies are limited and controversial. Therefore, we performed this meta-analysis to assess the relationship between D-dimer levels and prognostic and pathological characteristics of PC patients. We first searched the databases of PubMed, Embase, The Cochrane Library, Web Of Science, CBM, VIP, CNKI and Wanfang to identify available studies. The relationship between pretreatment d-dimer levels and prognosis in PC patients was assessed using the combined hazard ratio (HR) and 95% confidence interval (CI). The combined odds ratio (OR) and 95% confidence interval (CI) were used in assessing the relationship between pathological characteristics and d-dimer levels in PC patients. Stata 12.0 software was used for all statistical analyses. In total, we included 13 studies involving 2777 patients. The results showed that elevated pre-treatment d -dimer levels were significantly associated with OS deterioration (HR = 1.46 95% CI: 1.34-1.59; p < 0.001). We also performed subgroup analyses based on sample size, d -dimer threshold, follow-up time, and HR source to further validate the prognostic value of pretreatment d -dimer levels in PC. In addition, according to the analysis, high pretreatment d -dimer levels in PC patients were associated with late tumor stage (OR = 4.78, 95% CI 1.73-13.20, p < 0. 005), larger tumor size (OR = 1.72, 95% CI 1.25-2.35, p < 0.005), and distant metastasis of tumor (OR = 5.06, 95% CI 2.45-10.43, p < 0.005) were significantly associated. In contrast, other clinicopathological factors, including age, gender and lymph node metastasis, were not associated with d-dimer levels. In conclusion, we found that high pre-treatment d-dimer levels were associated with a poor prognosis in PC patients, in relation to later tumor stage, larger tumor size and the development of distant metastases. Plasma d-dimer levels can be used as a biomarker of prognosis in PC patients.

Life cycle assessment of n-caproic acid production via chain elongation from food waste: Comparison of shunting and staged technology.

n-Caproic acid is a widely used biochemical that can be produced from organic waste through chain elongation technology. This study aims to evaluate the environmental impacts of n-caproic acid production through chain elongation by two processes (i.e., shunting and staged technology). The Open-life cycle assessment (LCA) model was used to calculate the environmental impacts of both technologies based on experimental data. Results showed that the shunting technology had higher environmental impacts than the staged technology. Water and electricity made bigger contribution to the environmental impacts of both technologies. Reusing chain elongation effluent substituting for water and using electricity produced by wind power could reduce the environmental impacts of water and electricity effectively. Using ethanol from food waste had higher global warming potential than fossil ethanol, which suggested that a cradle-to-grave LCA is needed to be carried out for specific raw materials and chain elongation products in the future.

Structure and composition of dissolved organic matters in sludge by ultrasonic treatment.

The leaching of dissolved organic matter (DOM) from the sludge into the liquid phase is induced by ultrasound. However, there is limited investigation into the structure and molecular composition of sludge DOM in this process. The molecular structure and composition of sludge DOM in ultrasonic treatment were comprehensively elucidated in this study. The sludge dissolved organic carbon (DOC) and three-dimensional fluorescence spectroscopy (3D-EEM) image had most significant change at 15-min ultrasonic time and 1.2 W/mL ultrasonic density, respectively. Gas Chromatography-Mass Spectrometry (GC-MS) analysis indicated that ultrasonic treatment of sludge reduced the macromolecules to small molecules in DOM. Then, electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry (ESI FT-ICR-MS) analysis revealed that lignin, tannins, and carbohydrates were the main components of sludge DOMs after ultrasound treatment. analysis revealed that lignin, tannins, and carbohydrates were the main components of sludge DOMs after ultrasound treatment. Furthermore, through the Van Krevelen analysis, the major components were CHO (48.50%) and CHOS (23.20%) in the DOM of ultrasonicated sludge. This research provides the basis for the practical application of ultrasonic treatment of sludge and provides basic information for DOM components.

Insights into the influence of polystyrene microplastics on the bio-degradation behavior of tetrabromobisphenol A in soil.

Soil contamination by emerging pollutants tetrabromobisphenol A (TBBPA) and microplastics has become a global environmental issue in recent years. However, little is known about the effect of microplastics on degradation of TBBPA in soil, especially aged microplastics. In this study, the effect of aged polystyrene (PS) microplastics on the degradation of TBBPA in soil and the mechanisms were investigated. The results suggested that the aged microplastics exhibited a stronger inhibitory effect on the degradation of TBBPA in soil than the pristine microplastics, and the degradation efficiency of TBBPA decreased by 21.57% at the aged microplastic content of 1%. This might be related to the higher TBBPA adsorption capacity of aged microplastics compared to pristine microplastics. Aged microplastics strongly altered TBBPA-contaminated soil properties, reduced oxidoreductase activity and affected microbial community composition. The decrease in soil oxidoreductase activity and relative abundance of functional microorganisms (e.g., Bacillus, Pseudarthrobacter and Sphingomonas) caused by aged microplastics interfered with metabolic pathways of TBBPA. This study indicated the importance the risk assessment and soil remediation for TBBPA-contaminated soil with aged microplastics.

Predicting Endothelium-Dependent Diastolic Function (FMD) and Its Correlation with the Degree of Coronary Artery Disease (CAD) and Plaque Vulnerability for Cardiovascular Events.

Objective: This study aims to investigate the correlation between vascular endothelium-dependent diastolic function (FMD) and the degree of coronary artery disease (CAD), plaque vulnerability, and its predictive value for cardiovascular events. Methods: Initially, patients (n=100) who were admitted from January 2020 to January 2021 and intended to undergo percutaneous coronary intervention (PCI) were selected. Further, FMD in all patients was determined before the procedure and divided into a high-FMD group (≥4.2%) and a low-FMD group (<4.2%). Further, the data of two groups, including general information, coronary artery lesions, and plaque fibrous cap, were compared. Finally, the relationship between FMD and the degree of coronary artery lesions and plaque vulnerability was analyzed. Results: No significant differences were observed concerning general information, number of coronary arteries-associated branches, lesion type, involvement of the left main stem (LM), the proportion of chronic occluded lesions (CTO), and lipid pool angle between the low-FMD group and the high-FMD group (P > 0.05). Nevertheless, the degree of stenosis of the lesions in the low-FMD group was significantly higher than in the high-FMD group (P < 0.05). In addition, the thickness of the fibrous cap was considerably lower than that in the high-FMD group (P < 0.05). Moreover, the incidence rate of TCFA was significantly higher than the high-FMD group (P < 0.05). The correlation analysis showed that FMD was significantly negatively correlated with the degree of coronary artery lesion stenosis and TCFA (P < 0.05) and positively correlated with the fibrous cap thickness (P < 0.05). Conclusion: Overall, a negative correlation between FMD and the degree of coronary stenosis, plaque vulnerability, and a high predictive value for post-PCI cardiovascular events suggested that FMD could be a critical diagnostic marker for CAD.

Comprehensive carbon footprint analysis of wastewater treatment: A case study of modified cyclic activated sludge technology for low carbon source urban wastewater treatment.

To reduce pollution and carbon emissions, a quantitative evaluation of the carbon footprint of the wastewater treatment processes is crucial. However, micro carbon element flow analysis is rarely focused considering treatment efficiency of different technology. In this research, a comprehensive carbon footprint analysis is established under the micro carbon element flow analysis and macro carbon footprint analysis based on life cycle assessment (LCA). Three wastewater treatment processes (i.e., anaerobic anoxic oxic, A2O; cyclic activated sludge technology, CAST; modified cyclic activated sludge technology, M-CAST) for low carbon source urban wastewater are selected. The micro key element flow analysis illustrated that carbon source mainly flows to the assimilation function to promote microorganism growth. The carbon footprint analysis illustrated that M-CAST as the optimal wastewater treatment process had the lowest global warming potential (GWP). The key to reduce carbon emissions is to limit electricity consumption in wastewater treatment processes. Under the comprehensive carbon footprint analysis, M-CAST has the lowest environmental impact with low carbon emissions. The sensitivity analysis results revealed that biotreatment section variables considerably reduced the environmental impact on the LCA and the GWP, followed by the sludge disposal section. With this research, the optimization scheme can guide wastewater treatment plants to optimize relevant treatment sections and reduce pollution and carbon emissions.

Recent advances in ultrasound-Fenton/Fenton-like technology for degradation of aqueous organic pollutants.

Organic pollutants in water are a serious problem because of their widespread presence, harming the ecosystem and human health. Of the commonly used advanced oxidation processes, a hybrid of ultrasound and the Fenton/Fenton-like technology has received increasing attention in treatment of aqueous organic pollutants. This hybrid is effective in degradation of organic pollutants, but its application has not been summarised. Herein, first, the application and influencing factors of this hybrid technology for organic pollutants degradation are introduced. Second, the mechanism of its action is discussed. Third, the current challenges and future perspectives associated with this technology are proposed. This review provides valuable information regarding this technology, deepens the understanding of its mechanisms of organic pollutants degradation and provides a reference for its use in treatment of aquatic environments.

Effect of high corn straw loads on short-chain fatty acid production in semi-continuous rumen reactor.

Ruminal microorganisms can efficiently hydrolyze biomass waste for short-chain fatty acid (SCFA) production. However, the continuous SCFA production by ruminal microorganisms at high loads is unclear. In this study, the effectiveness of a rumen semi-continuous reactor at high load for SCFA production was explored. Results showed that SCFA concentration reached 13.3 g/L at 8 % (w/v) corn straw load. The higher the corn straw load, the lower the volatile solid removal. Rumen microbial community composition changed significantly with increasing corn straw load. A significant decrease in bacterial diversity and abundance was observed at 8 % corn straw load. Some core genera such as Prevotella, Saccharofermentans, and Ruminococcus significantly increased. As corn straw loads increased, the expression of functional genes related to hydrolysis and acidogenesis gradually increased. Thus, the 8.0 % load is suitable for SCFA production. These findings provide new insights into high load fermentation of ruminal microorganisms.

Safety, Immunogenicity, and Mechanism of a Rotavirus mRNA-LNP Vaccine in Mice.

Rotaviruses (RVs) are a major cause of diarrhea in young children worldwide. The currently available and licensed vaccines contain live attenuated RVs. Optimization of live attenuated RV vaccines or developing non-replicating RV (e.g., mRNA) vaccines is crucial for reducing the morbidity and mortality from RV infections. Herein, a nucleoside-modified mRNA vaccine encapsulated in lipid nanoparticles (LNP) and encoding the VP7 protein from the G1 type of RV was developed. The 5' untranslated region of an isolated human RV was utilized for the mRNA vaccine. After undergoing quality inspection, the VP7-mRNA vaccine was injected by subcutaneous or intramuscular routes into mice. Mice received three injections in 21 d intervals. IgG antibodies, neutralizing antibodies, cellular immunity, and gene expression from peripheral blood mononuclear cells were evaluated. Significant differences in levels of IgG antibodies were not observed in groups with adjuvant but were observed in groups without adjuvant. The vaccine without adjuvant induced the highest antibody titers after intramuscular injection. The vaccine elicited a potent antiviral immune response characterized by antiviral clusters of differentiation CD8+ T cells. VP7-mRNA induced interferon-γ secretion to mediate cellular immune responses. Chemokine-mediated signaling pathways and immune response were activated by VP7-mRNA vaccine injection. The mRNA LNP vaccine will require testing for protective efficacy, and it is an option for preventing rotavirus infection.

Sulfur-manganese carbonate composite autotrophic denitrification: nitrogen removal performance and biochemistry mechanism.

A novel composite sulfur-manganese carbonate autotrophic denitrification (SMAD) system was developed to reduce sulfate production and provide pH buffer function while improving denitrification efficiency without external organics. The average removal efficiency of total nitrogen (TN) was 98.09% and 96.29%, and that of NO3--N was 99.53% and 97.77%, respectively, in the SMAD system with a hydraulic retention time (HRT) of 6 h and 3 h. They were significantly higher than that in the controls (quartz sand, manganese carbonate ore, and sulfur systems). The H+ produced by the sulfur autotrophic denitrification (SAD) process promoted the release of Mn2+ in the SMAD system. And this system had a stable pH with no accumulation of NO2--N. The decrease of sulfate and formation of Mn oxides through Mn2+ electron donation confirmed the presence of the manganese autotrophic denitrification (MAD) process in the SMAD system. Dominant functional bacteria in the SMAD system were Thiobacillus, Chlorobium, and Sulfurimonas, which were linked to nitrogen, sulfur, and manganese conversion and promoted denitrification. Meanwhile, Flavobacterium participating in Mn2+ oxidation was found only in the SMAD system. The SMAD system provided a new strategy for advanced tailwater treatment.

Rumen microbes, enzymes, metabolisms, and application in lignocellulosic waste conversion - A comprehensive review.

The rumen of ruminants is a natural anaerobic fermentation system that efficiently degrades lignocellulosic biomass and mainly depends on synergistic interactions between multiple microbes and their secreted enzymes. Ruminal microbes have been employed as biomass waste converters and are receiving increasing attention because of their degradation performance. To explore the application of ruminal microbes and their secreted enzymes in biomass waste, a comprehensive understanding of these processes is required. Based on the degradation capacity and mechanism of ruminal microbes and their secreted lignocellulose enzymes, this review concentrates on elucidating the main enzymatic strategies that ruminal microbes use for lignocellulose degradation, focusing mainly on polysaccharide metabolism-related gene loci and cellulosomes. Hydrolysis, acidification, methanogenesis, interspecific H2 transfer, and urea cycling in ruminal metabolism are also discussed. Finally, we review the research progress on the conversion of biomass waste into biofuels (bioethanol, biohydrogen, and biomethane) and value-added chemicals (organic acids) by ruminal microbes. This review aims to provide new ideas and methods for ruminal microbe and enzyme applications, biomass waste conversion, and global energy shortage alleviation.

Unraveling biological behavior and influence of magnetic iron-based nanoparticles in algal-bacterial systems: A comprehensive review.

Magnetic iron-based nanoparticles have been found to stimulate algae growth and harvest, repair disintegrated particles and improve stability, and facilitate operation in extreme environments, which help improve the wide application of algal-bacterial technology. Nevertheless, up to now, no literature collected to systematically review the research progress of on the employment of magnetic iron-based nanoparticles in the algal-bacterial system. This review summarizes the special effects (e.g., size effect, surface effect and biological effect) and corresponding properties of magnetic iron-based nanoparticles (e.g., magnetism, adsorption, electricity, etc.), which is closely related to biological effects and algal-bacterial behaviors. Additionally, it was found that magnetic iron-based nanoparticles offer remarkable impacts on improving the growth and metabolism of algal-bacterial consortia and the mechanisms mainly include its possible iron uptake pathways in bacteria and/or algae cells, as well as the magnetic biological effect of magnetic iron-based nanoparticles on algae-bacteria growth. Furthermore, in terms of the mechanism for establishing the algae-bacteria symbiotic relationship, the most recent works reveal that the charge effect, material transfer and signal transmission of magnetic iron-based nanoparticles possess a large array of potential mechanisms by which it can affect the establishment of algal-bacterial symbiosis. This discussion is expected to promote the progress of magnetic iron-based nanoparticles, as an eco-friendly, convenient and cost-effective technology that can be applied in algal-bacterial wastewater treatment fields.

Prediction of Hydrogel Degradation Time Based on Central Composite Design.

In this study, a self-degrading hydrogel was formed by free-radical-initiated copolymerization, which can be used for oil and gas well strip pressure operations. Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H NMR), scanning electron microscopy (SEM), and thermogravimetry-mass spectrometry (TGA-MS) were used to study the reaction mechanism as well as the microstructure of the gels. Then, the effects of the four factors and their interactions on gel degradation time were determined by central composite design (CCD). Then, the effects of copolymer concentration, cross-linker, initiator, and reaction temperature and their interactions on gel degradation time were determined by central composite design (CCD), and the corresponding second-order polynomial models were generated. Finally, the gelation conditions were optimized by a response surface methodology and verified by degradation experiments. Both FTIR and 1H NMR indicated that the gel was formed by a copolymerization reaction between the monomer and the cross-linker. SEM showed that the gel structure collapsed, which was caused by the poor mechanical properties of the gel, but it was also able to withstand some wellbore pressure and degraded more easily. TGA-MS showed that the gel possessed good degradation properties. In addition, analysis of variance (ANOVA) showed that the second-order polynomial model was highly significant. The results also showed that the expected values of the gelation conditions optimized by the response surface methodology did not differ significantly from the actual values. The degradation model can be used to predict the degradation time of the gel and optimization of gelation conditions. This study can help petroleum engineers in applying self-degrading gels to seal the wellbore pressure.

Bioconversion of volatile fatty acids from organic wastes to produce high-value products by photosynthetic bacteria: A review.

Anaerobic fermentation of organic waste to produce volatile fatty acids (VFAs) production is a relatively mature technology. VFAs can be used as a cheap and readily available carbon source by photosynthetic bacteria (PSB) to produce high value-added products, which are widely used in various applications. To better enhance the VFAs obtained from organic wastes for PSB to produce high value-added products, a comprehensive review is needed, which is currently not available. This review systematically summarizes the current status of microbial proteins, H2, poly-ß-hydroxybutyrate (PHB), coenzyme Q10 (CoQ10), and 5-aminolevulinic acid (ALA) production by PSB utilizing VFAs as a carbon resource. Meanwhile, the metabolic pathways involved in the H2, PHB, CoQ10, and 5-ALA production by PSB were deeply explored. In addition, a systematic resource utilization pathway for PSB utilizing VFAs from anaerobic fermentation of organic wastes to produce high value-added products was proposed. Finally, the current challenges and priorities for future research were presented, such as the screening of efficient PSB strains, conducting large-scale experiments, high-value product separation, recovery, and purification, and the mining of metabolic pathways for the VFA utilization to generate high value-added products by PSB.

Response of rumen microorganisms to pH during anaerobic hydrolysis and acidogenesis of lignocellulose biomass.

Rumen microorganisms can efficiently degrade lignocellulosic wastes to produce volatile fatty acids (VFAs). pH is a key factor in controlling the type and yield of VFAs by affecting the microorganisms involved in rumen fermentation. However, the effects of different pH on rumen microbial diversity, communities, and mechanisms are unclear. In this study, the hydrolysis and acidogenesis of corn straw and diversity, communities, and mechanisms of rumen microorganisms were explored at different initial pHs. Results showed that the highest hemicellulose, cellulose, and lignin degradation efficiency of corn straw was 55.2 %, 38.3 %, and 7.01 %, respectively, and VFA concentration was 10.2 g/L at pH 7.0. Low pH decreased the bacterial diversity and increased the fungal diversity. Rumen bacteria and fungi had different responses to initial pHs, and the community structure of bacteria and fungi had obviously differences at the genus level. The core genera Succiniclasticum, Treponema, and Neocallimastix relative abundance at initial pH 7.0 samples were significantly higher than that at lower initial pHs, reaching 6.01 %, 1.61 %, and 5.35 %, respectively. The bacterial network was more complex than that of fungi. pH, acetic acid, and propionic acid were the main factors influencing the bacterial and fungal community structure. Low pH inhibited the expression of functional genes related to hydrolysis and acidogenesis, explaining the lower hydrolysis and acidogenesis efficiency. These findings will provide a better understanding for rumen fermentation to produce VFAs.

Regulation of extracellular polymers based on quorum sensing in wastewater biological treatment from mechanisms to applications: A critical review.

Extracellular polymeric substances (EPS) regulated by quorum sensing (QS) could directly mediate adhesion between microorganisms and form tight microbial aggregates. Besides, EPS have redox properties, which can facilitate electron transfer for promoting electroactive bacteria. Currently, the applications research on improving wastewater biological treatment performance based on QS regulated EPS have been widely reported, but reviews on the level of QS regulated EPS to enhance EPS function in microbial systems are still lacking. This work proposes the potential mechanisms of EPS synthesis by QS regulation from the viewpoint of material metabolism and energy metabolism, and summarizes the effects of QS on EPS synthesis. By synthesizing the role of QS in EPS regulation, we further point out the applications of QS-regulated EPS in wastewater biological treatment, which involve a series of aspects such as strengthening microbial colonization, mitigating membrane biofouling, improving the shock resistance of microbial metabolic systems, and strengthening the electron transfer capacity of microbial metabolic systems. According to this comprehensive review, future research on QS-regulated EPS should focus on the exploration of the micro-mechanisms, and economic regulation strategies for QS-regulated EPS should be developed, while the stability of QS-regulated EPS in long-term production experimental research should be further demonstrated.